The present invention relates to power transmission of a turning-track track-laying vehicle, in which there is a closed-loop type track belt arranged between end rolls or similar in such a way that one edge of the track belt can be stretched and the other edge of the track belt contracted in order to make the vehicle execute a turn, which vehicle comprises a motor, a traction sprocket or sprockets, and power transmission equipment between the traction sprocket or sprockets and the motor, which drive sprocket or sprockets are positioned above the top run of the track belt, preferably sideways in its middle range, and in which traction sprocket or sprockets there are drive cogs or similar, which drive cogs are in driving contact with the openings, grooves or similar of the track belt, so that the traction force can be transmitted from the traction sprocket or sprockets to the track belt.
The object of the present invention is to provide such transmission for a turning-track vehicle, by means of which the power is transmitted from a motor which is specifically located outside the track-belt loop to drive the track belt so that the track belt may be more advantageously curved than before, and that the previously noted drawbacks, which will be discussed below, can be avoided.
The present invention may be used in all turning-track vehicles, either in those in which either the front end or the rear end of the track belt is forcedly controlled, or in those in which both ends are controlled by stretching one side of the track belt and by contracting the other edge in a similar way.
In the Prior Art, in turning-track vehicles, whose motor and power transmission are located outside the track belt loop, such an axially fixed traction sprocket is used which is positioned above the upper run of the track belt in its center area. In known transmission systems which lateral forces have been created to the side walls of the traction sprocket or sprockets; the forces are the higher the sharper is the bend and higher is the traction force of the vehicle. Said fixed traction sprocket or sprockets have also considerably increased the steering forces because the "tight" fit of the traction openings prevents the upper run of the track belt from adjusting itself in the position required by the turning radius of the vehicle.